The Patent Literature 1 listed below discloses a waveguide strip line transducer for transducing a transmission mode of an electromagnetic wave such as a microwave or a millimeter wave, for example.
The waveguide strip line transducer includes a hollow waveguide having a rectangular cross-sectional shape.
A substrate is provided on the upper side of one tube wall among four tube walls forming the hollow waveguide, and a strip line is wired on a front surface of the substrate.
In addition, a hole is provided in the one tube wall on which the substrate is provided, and a probe connected to the strip line is arranged at the position of the hole provided in the one tube wall such that an end of the probe is at a position of the tube interior in the hollow waveguide.
Note that, in a power feed circuit for feeding power to a plurality of antenna elements forming an array antenna, generally, the same number of waveguide strip line transducers as the number of the plurality of antenna elements is mounted.